Different types of wire connectors are known in the art, one type of electrical connector is a terminal lug connector, which is typically secured to an end of a single electrical wire by crimping or soldering the wire to the lug connector. These types of wire connectors, which are attached to the end of a single wire usually have a hole therein so the lug can be attached to a bus bar or the like by a threaded fastener. These types of terminal lug connectors are usually not electrically isolated from their surroundings.
Another type of electrical wire connector is the type used to join two or more wires into an electrical connection. A well-known and popular example of a wire connector to join two or more wires is the twist-on wire connector. Typically, when two or more wires are electrically joined in a twist-on wire connector the wire connector simultaneously forms an electrical wire junction and electrically insulates the wire junction from the surroundings as the connector housing is twisted with respect to the wires therein. These types of twist-on wire connector are usually concealed from view by a junction box or in some cases by burying the wire connector underground.
When electrical problems occur in an electrical circuit the problem often times occur in or proximate an electrically insulated wire connector. If a fault arises in a twist-on wire connector such as a faulty electrical junction all the twist-on wire connectors may have to be found and inspected since the twist-on wire connectors are oftentimes concealed from view within junction boxes or the like. Aside from locating a fault in an electrical circuit there are also environmental conditions that may lead to faults, for example, if the temperature in the twist-on wire connector increases or changes rapidly it may be a preliminary indication that an electrical junction between the wires is about to fail. This is particularly true in electrical twist-on wire connectors where the electrical wires are held in pressure contact by a member within the housing of the wire connector.
In other cases one may want to monitor environmental conditions proximate a wire connector as such conditions may indicate that either the junction between the wires is about to fail or equipment connected to the electrical circuit is about to fail which may change environmental conditions proximate the wire connector. Typical environmental conditions that may be indication of a problem include excessive moisture, extreme temperature and in some cases excessive or inadequate pressure.
In still other cases one may want to monitor environmental conditions proximate an electrical circuit for purposes not related to the operation of the electrical circuit.
Electrical wire connectors for joining two or more wires, such as twist-on wire connectors, are usually concealed in junction boxes or behind walls or even underground. The concealment of the electrical wire connector makes it time consuming to locate an electrical connector with a faulty electrical junction. In still other cases the wire connectors may be visible but the problem is not immediately apparent since the electrical junction within a wire connector is shielded from view by the insulated housing or shell on the exterior of the wire connector.
Microprocessor animal implants, which contain passive RFID tags, are known in the art and have been used to contain static information on the animal carrying the implant or the owner of the animal. Similarly, passive RFID tags have been attached to products shipped in commerce for purpose of inventory tracking and inventory management. Typically, in animals such as pets a passive RFID tag may be implanted in the ear of the pet with the passive RFID tag containing static information on the owner as well as static information on the health of the animal. Through use of an external RFID reader the information can be downloaded from the passive RFID tag to help locate information on the owner of a lost pet or to determine if the pet has received the proper immunizations. In other cases the passive RFID tag may be used for inventory tracking and management by attaching the passive RFID tags directly to containers or goods to enable tracking of the containers or the goods which can be used to improve the efficiency of the inventory management of the goods as the goods are shipped from manufacture to a retail or commercial outlet. In either case through use of a RFID reader one can quickly determine useful static information related to the animal or goods associated with the passive RFID tag. Typically, the passive RFID tag contains a microprocessor for processing information and an antenna for receiving and transmitting information. Some types of passive RFID tags contain batteries while others do not. Typically, passive RFID tags operate in the radio frequency which ranges from 3K Hz to 300 GHz.
U.S. Pat. No. 7,306,489 discloses a heat sensitive coating on a terminal lug. The heat sensitive coating, which is placed on a portion of the electrically conducting region of the terminal lug, either changes color or melts in response to a change in temperature of the terminal lug. Typically, terminal lugs have a tubular end that is secured to an end of a wire by inserting the wire end therein and either crimping the tubular end to the wire end or soldering the wire end to the tubular end of the terminal lug. To protect a heat sensitive coating on the terminal lug from environmental conditions, which are external to the terminal lug, the inventor places a thermal shield over the heat sensitive coating. In one of his examples the performance indicator, which is a color changing paint, is applied to a terminal lug, which when crimped, retains enough of the performance indicator to provide a visual indication of the color change. In another example the heat sensitive coating is applied to the housing of his terminal lug. In alternate embodiments the inventor adhesively adheres a passive RFID tag, which may contain a sensor such as pressure sensor, a strain sensor, a temperature sensor or a humidity sensor, on his terminal lug. In another example multiple passive RFID tags are placed on his terminal lug with the incoming radio frequency signal used to power the passive RFID tag to enable the RFID tag to transmit information to an RFID reader.